Merge branch 'main' into jsr45

Author: Tetchki

.github/ISSUE_TEMPLATE/feature.md

@@ -1,10 +1,10 @@
 ---
 name: "\U0001F389 Suggest a feature"
-about: Please create a feature request here https://github.com/lampepfl/dotty-feature-requests
+about: Please create a feature request here https://github.com/lampepfl/dotty/discussions/new?category=feature-requests
 title: ''
 labels: ''
 assignees: ''
 
 ---
 
-Please create a feature request here: [lampepfl/dotty-feature-requests](https://github.com/lampepfl/dotty-feature-requests).
+Please create a feature request in the [Dotty Discussions](https://github.com/lampepfl/dotty/discussions/new?category=feature-requests).

.github/workflows/ci.yaml

@@ -253,7 +253,7 @@ jobs:
 
       - name: MiMa
         run: |
-          ./project/scripts/sbt ";scala3-interfaces/mimaReportBinaryIssues ;scala3-library-bootstrapped/mimaReportBinaryIssues ;scala3-library-bootstrappedJS/mimaReportBinaryIssues; tasty-core-bootstrapped/mimaReportBinaryIssues"
+          ./project/scripts/sbt ";scala3-interfaces/mimaReportBinaryIssues ;scala3-library-bootstrapped/mimaReportBinaryIssues ;scala3-library-bootstrappedJS/mimaReportBinaryIssues; tasty-core-bootstrapped/mimaReportBinaryIssues; stdlib-bootstrapped/mimaReportBinaryIssues"
 
   community_build_a:
     runs-on: [self-hosted, Linux]

.github/workflows/scaladoc.yaml

@@ -4,9 +4,11 @@ on:
   push:
     branches-ignore:
       - 'language-reference-stable'
+      - 'gh-readonly-queue/**'
   pull_request:
     branches-ignore:
       - 'language-reference-stable'
+  merge_group:
 permissions:
   contents: read
 
@@ -15,7 +17,8 @@ jobs:
     env:
       AZURE_STORAGE_SAS_TOKEN: ${{ secrets.AZURE_STORAGE_SAS_TOKEN }}
     runs-on: ubuntu-latest
-    if: "(    github.event_name == 'pull_request'
+    if: "github.event_name == 'merge_group'
+         || (    github.event_name == 'pull_request'
            && !contains(github.event.pull_request.body, '[skip ci]')
            && !contains(github.event.pull_request.body, '[skip docs]')
          )

.vscode-template/settings.json

@@ -9,6 +9,7 @@
     "**/*.class": true,
     "**/*.tasty": true,
     "**/target/": true,
-    "community-build/community-projects": true
+    "community-build/community-projects": true,
+    "tests/pos-with-compiler-cc/dotc/**/*.scala": true
   }
 }

CONTRIBUTING.md

@@ -2,4 +2,4 @@
 
 Firstly, thanks for being willing to contribute to Dotty! Head on over the
 [Scala 3 Contributing
-Guide](https://docs.scala-lang.org/scala3/guides/contribution/contribution-intro.html), which should have all the info you're looking for.
+Guide](https://dotty.epfl.ch/docs/contributing/index.html), which should have all the info you're looking for.

MAINTENANCE.md

@@ -16,6 +16,11 @@ The issue supervisor is responsible for:
     - Attempting to reproduce the issue (or label “stat:cannot reproduce”)
     - Further minimizing the issue or asking the reporter of the issue to minimize it correctly (or label “stat:needs minimization”)
   - Identifying which issues are of considerable importance and bringing them to the attention of the team during the Dotty meeting, where they can be filtered and added to the [Future Versions](https://github.com/lampepfl/dotty/milestone/46) milestone.
+  - Identifying if a report is really a feature request and if so, converting it to
+    a [feature request discussion](https://github.com/lampepfl/dotty/discussions/categories/feature-requests).
+- Keeping an eye on new
+[discussions](https://github.com/lampepfl/dotty/discussions), making sure they
+don't go unanswered and also correctly labeling new feature requests.
 
 Other core teammates are responsible for providing information to the issue supervisor in a timely manner when it is requested if they have that information.
 
@@ -32,7 +37,6 @@ The issue supervisor schedule is maintained in the [Issue Supervisor Statistics
 An issue supervisor needs to have all the accesses and privileges required to get their job done. This might include:
 
 - Admin rights in lampepfl/dotty repository
-- Admin rights in lampepfl/dotty-feature-requests repository
 - Permission to create new repositories in lampepfl organization (needed to fork repositories for the community build)
 - Access to the LAMP slack to be able to ask for help with the infrastructure, triaging and such
 
@@ -61,28 +65,36 @@ At the end of their supervision period, the supervisor reports to the team durin
 
 The following is the list of all the principal areas of the compiler and the core team members who are responsible for their maintenance:
 
+### Compiler
 - Parser: @odersky
 - Typer: @odersky, @smarter, (@dwijnand)
 - Erasure: @smarter, @odersky
 - Enums: @bishabosha
+- Derivation & Mirrors: @bishabosha, (@dwijnand)
 - Export: @bishabosha, @odersky
 - Pattern Matching: @dwijnand, (@liufengyun), @sjrd
 - Inline: @nicolasstucki, @odersky
-- Metaprogramming (Quotes, Reflect, Staging): @nicolasstucki, @aherlihy
-- Match types: @OlivierBlanvillain, @dwijnand
-- GADT: @abgruszecki, @dwijnand
-- Scaladoc: @KacperFKorban,  @BarkingBad, @pikinier20
-- Initialization checker: @olhotak, @liufengyun, @anatoliykmetyuk
+- Metaprogramming (Quotes, Reflect, Staging): @nicolasstucki, @jchyb
+- Match types: @sjrd, @dwijnand, @Decel
+- GADT: @dwijnand, @Linyxus
+- Initialization checker: @olhotak, @liufengyun
 - Safe nulls: @noti0na1, @olhotak
+- Lazy vals: @szymon-rd, @sjrd
 - tailrec: @sjrd, @mbovel
 - JS backend: @sjrd
-- forward compat (-scala-release): @prolativ, @Kordyjan, (@nicolasstucki)
-- Benchmarks: @anatoliykmetyuk, @mbovel
-- REPL: @dwijnand, @anatoliykmetyuk, @prolativ
+- JVM backend: @sjrd
+- Java-compat: @smarter
+
+### Tooling
+- REPL: @dwijnand, @prolativ
+- Scaladoc: @Florian3k
+- SemanticDB: @tanishiking
+- Coverage: @TheElectronWill
+- Linting (especially unused warnings) / Reporting UX: @szymon-rd
+
+### Infrastructure
 - CI: @anatoliykmetyuk
 - Community Build: @anatoliykmetyuk
+- Open Community Build: @WojciechMazur
 - Vulpix: @dwijnand, @prolativ
-- JVM backend: @Kordyjan, (@sjrd)
-- Derivation & Mirrors: @bishabosha, (@dwijnand)
-- Linting (especially unused warnings) / Reporting UX: VirtusLab TBD?
-- Java-compat: @Kordyjan
+- Benchmarks: @mbovel

compiler/src/dotty/tools/dotc/CompilationUnit.scala

@@ -157,7 +157,7 @@ object CompilationUnit {
       if tree.symbol.is(Flags.Inline) then
         containsInline = true
       tree match
-        case tpd.Quote(_) =>
+        case _: tpd.Quote =>
           containsQuote = true
         case tree: tpd.Apply if tree.symbol == defn.QuotedTypeModule_of =>
           containsQuote = true

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -338,9 +338,9 @@ object desugar {
   def quotedPattern(tree: untpd.Tree, expectedTpt: untpd.Tree)(using Context): untpd.Tree = {
     def adaptToExpectedTpt(tree: untpd.Tree): untpd.Tree = tree match {
       // Add the expected type as an ascription
-      case _: untpd.Splice =>
+      case _: untpd.SplicePattern =>
         untpd.Typed(tree, expectedTpt).withSpan(tree.span)
-      case Typed(expr: untpd.Splice, tpt) =>
+      case Typed(expr: untpd.SplicePattern, tpt) =>
         cpy.Typed(tree)(expr, untpd.makeAndType(tpt, expectedTpt).withSpan(tpt.span))
 
       // Propagate down the expected type to the leafs of the expression
@@ -637,7 +637,10 @@ object desugar {
     //       new C[...](p1, ..., pN)(moreParams)
     val (caseClassMeths, enumScaffolding) = {
       def syntheticProperty(name: TermName, tpt: Tree, rhs: Tree) =
-        DefDef(name, Nil, tpt, rhs).withMods(synthetic)
+        val mods =
+          if ctx.settings.Yscala2Stdlib.value then synthetic | Inline
+          else synthetic
+        DefDef(name, Nil, tpt, rhs).withMods(mods)
 
       def productElemMeths =
         val caseParams = derivedVparamss.head.toArray
@@ -735,13 +738,25 @@ object desugar {
               .withMods(appMods) :: Nil
           }
         val unapplyMeth = {
+          def scala2LibCompatUnapplyRhs(unapplyParamName: Name) =
+            assert(arity <= Definitions.MaxTupleArity, "Unexpected case class with tuple larger than 22: "+ cdef.show)
+            if arity == 1 then Apply(scalaDot(nme.Option), Select(Ident(unapplyParamName), nme._1))
+            else
+              val tupleApply = Select(Ident(nme.scala), s"Tuple$arity".toTermName)
+              val members = List.tabulate(arity) { n => Select(Ident(unapplyParamName), s"_${n+1}".toTermName) }
+              Apply(scalaDot(nme.Option), Apply(tupleApply, members))
+
           val hasRepeatedParam = constrVparamss.head.exists {
             case ValDef(_, tpt, _) => isRepeated(tpt)
           }
           val methName = if (hasRepeatedParam) nme.unapplySeq else nme.unapply
           val unapplyParam = makeSyntheticParameter(tpt = classTypeRef)
-          val unapplyRHS = if (arity == 0) Literal(Constant(true)) else Ident(unapplyParam.name)
+          val unapplyRHS =
+            if (arity == 0) Literal(Constant(true))
+            else if ctx.settings.Yscala2Stdlib.value then scala2LibCompatUnapplyRhs(unapplyParam.name)
+            else Ident(unapplyParam.name)
           val unapplyResTp = if (arity == 0) Literal(Constant(true)) else TypeTree()
+
           DefDef(
             methName,
             joinParams(derivedTparams, (unapplyParam :: Nil) :: Nil),
@@ -1824,16 +1839,6 @@ object desugar {
         flatTree(pats1 map (makePatDef(tree, mods, _, rhs)))
       case ext: ExtMethods =>
         Block(List(ext), Literal(Constant(())).withSpan(ext.span))
-      case CapturingTypeTree(refs, parent) =>
-        // convert   `{refs} T`   to `T @retains refs`
-        //           `{refs}-> T` to `-> (T @retainsByName refs)`
-        def annotate(annotName: TypeName, tp: Tree) =
-          Annotated(tp, New(scalaAnnotationDot(annotName), List(refs)))
-        parent match
-          case ByNameTypeTree(restpt) =>
-            cpy.ByNameTypeTree(parent)(annotate(tpnme.retainsByName, restpt))
-          case _ =>
-            annotate(tpnme.retains, parent)
       case f: FunctionWithMods if f.hasErasedParams => makeFunctionWithValDefs(f, pt)
     }
     desugared.withSpan(tree.span)
@@ -1927,7 +1932,7 @@ object desugar {
         }
         tree match
           case tree: FunctionWithMods =>
-            untpd.FunctionWithMods(applyVParams, tree.body, tree.mods, tree.erasedParams)
+            untpd.FunctionWithMods(applyVParams, result, tree.mods, tree.erasedParams)
           case _ => untpd.Function(applyVParams, result)
     }
   }
@@ -1986,15 +1991,13 @@ object desugar {
         trees foreach collect
       case Block(Nil, expr) =>
         collect(expr)
-      case Quote(body) =>
+      case Quote(body, _) =>
         new UntypedTreeTraverser {
           def traverse(tree: untpd.Tree)(using Context): Unit = tree match {
-            case Splice(expr) => collect(expr)
+            case SplicePattern(body, _) => collect(body)
             case _ => traverseChildren(tree)
           }
         }.traverse(body)
-      case CapturingTypeTree(refs, parent) =>
-        collect(parent)
       case _ =>
     }
     collect(tree)

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -223,9 +223,6 @@ trait TreeInfo[T <: Untyped] { self: Trees.Instance[T] =>
   /** Strip `=> T` to `T` and (under pureFunctions) `{refs}-> T` to `T` */
   def stripByNameType(tree: Tree)(using Context): Tree = unsplice(tree) match
     case ByNameTypeTree(t1) => t1
-    case untpd.CapturingTypeTree(_, parent) =>
-      val parent1 = stripByNameType(parent)
-      if parent1 eq parent then tree else parent1
     case _ => tree
 
   /** All type and value parameter symbols of this DefDef */
@@ -467,19 +464,21 @@ trait UntypedTreeInfo extends TreeInfo[Untyped] { self: Trees.Instance[Untyped]
     }
   }
 
-  /** Under pureFunctions: A builder and extractor for `=> T`, which is an alias for `{*}-> T`.
-   *  Only trees of the form `=> T` are matched; trees written directly as `{*}-> T`
+  /** Under pureFunctions: A builder and extractor for `=> T`, which is an alias for `->{cap} T`.
+   *  Only trees of the form `=> T` are matched; trees written directly as `->{cap} T`
    *  are ignored by the extractor.
    */
   object ImpureByNameTypeTree:
 
-    def apply(tp: ByNameTypeTree)(using Context): untpd.CapturingTypeTree =
-      untpd.CapturingTypeTree(
-        untpd.captureRoot.withSpan(tp.span.startPos) :: Nil, tp)
+    def apply(tp: Tree)(using Context): untpd.ByNameTypeTree =
+      untpd.ByNameTypeTree(
+        untpd.CapturesAndResult(
+          untpd.captureRoot.withSpan(tp.span.startPos) :: Nil, tp))
 
-    def unapply(tp: Tree)(using Context): Option[ByNameTypeTree] = tp match
-      case untpd.CapturingTypeTree(id @ Select(_, nme.CAPTURE_ROOT) :: Nil, bntp: ByNameTypeTree)
-      if id.span == bntp.span.startPos => Some(bntp)
+    def unapply(tp: Tree)(using Context): Option[Tree] = tp match
+      case untpd.ByNameTypeTree(
+        untpd.CapturesAndResult(id @ Select(_, nme.CAPTURE_ROOT) :: Nil, result))
+      if id.span == result.span.startPos => Some(result)
       case _ => None
   end ImpureByNameTypeTree
 }

compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala

@@ -146,11 +146,6 @@ class TreeTypeMap(
           val bind1 = tmap.transformSub(bind)
           val expr1 = tmap.transform(expr)
           cpy.Labeled(labeled)(bind1, expr1)
-        case tree @ Hole(_, _, args, content, tpt) =>
-          val args1 = args.mapConserve(transform)
-          val content1 = transform(content)
-          val tpt1 = transform(tpt)
-          cpy.Hole(tree)(args = args1, content = content1, tpt = tpt1)
         case tree1 =>
           super.transform(tree1)
       }